1. Field of the Invention
The present invention relates to methods of writing to, reading from and erasing information on a data storage medium.
2. Description of the Prior Art
Various attempts have been made to design higher density data storage media for computer devices to replace conventional storage media such as magnetic disks, CD-ROMs, DVDs, etc. Many of the obstacles faced with respect to developing improved data storage methods have been associated with inadequate storage material properties. For example, photopolymers have been investigated for use in one-bit or holographic data storage. However, photopolymers exhibit strong dimensional shrinkage. Also, most photo-sensitive polymers may be used only as WORM media (write once, read many times) and the rewritable photopolymers are still unstable and show significant fatigue when write-read cycles are repeated many times. Even write-once fluorescent photopolymers show strong reduction of fluorescent output signals when read repeatedly. An additional problem with most photopolymers, as well as for photorefractive crystals, another potential material for volumetric one-bit recording, is the necessity of using a femto-second high peak power Ti-sapphire laser to achieve efficient two-photon absorption. This type of laser is big, expensive and suitable only for laboratory demonstration.
Therefore, there exists a need for better materials for making high density data storage devices.